A total of 1547 bacterial strains recovered from recycling irrigation systems were evaluated *in vitro* and *in planta* for their biological control efficacy against boxwood (*Buxus* spp.) blight caused by *Calonectria pseudonaviculata* (*Cps*), an emerging fungal disease in the United States. *Pseudomonas protegens* strains produced antifungal secondary metabolites that reduced *Cps* growth and infection.